Question

Write a Java program that creates a two-dimensional array of type integer of size x by y (x and y must be entered by the user). The program must fill the array with random numbers from 1 to 9. Then, the program must print the original array and the elements that are in even columns of the array.

Answer 1

The java program is as follows:

import java.util.*;

public class Main{

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

Random r = new Random();

int x, y;

x = input.nextInt();

y = input.nextInt();

int[][] Array2D = new int[x][y];

for(int i = 0; i < x ; i++){

for(int j = 0; j < y; j++){ Array2D[i][j] = r.nextInt(9) + 1; }

}

for(int i = 0; i < x ; i++){

for(int j = 0; j < y; j++){ System.out.print(Array2D[i][j]+" "); }

System.out.println();

}

for(int i = 0; i < x ; i++){

for(int j = 1; j < y; j+=2){ System.out.print(Array2D[i][j]+" "); }

System.out.println();

}

}

}

Step-by-step explanation:

This creates a random object

Random r = new Random();

This declares x and y as integers

int x, y;

This gets input for x

x = input.nextInt();

This gets input for y

y = input.nextInt();

This declares the 2D array

int[][] Array2D = new int[x][y];

The following iteration populates the array with integers 1 to 9

for(int i = 0; i < x ; i++){

for(int j = 0; j < y; j++){ Array2D[i][j] = r.nextInt(9) + 1; }

}

The following iteration prints all elements of the array

for(int i = 0; i < x ; i++){

for(int j = 0; j < y; j++){ System.out.print(Array2D[i][j]+" "); }

System.out.println();

}

The following iteration prints all elements on the even column

for(int i = 0; i < x ; i++){

for(int j = 1; j < y; j+=2){ System.out.print(Array2D[i][j]+" "); }

System.out.println();

}